It is tempting to try to find meaning in the so-called “A-share premium”. This is the persistent valuation gap between the shares of Chinese companies that trade in Shanghai or Shenzhen (known as A-shares) and the shares of the same companies that trade in Hong Kong (H shares).

For much of 2019 the A-share premium has been roughly 20-30 per cent, meaning that A-shares are 20-30 per cent more expensive than equivalent H shares. Some companies, such as Chinese brokers, trade at several times the price of their Hong Kong equivalents. While this premium has persisted for years, it can vary greatly, from 100 per cent in the great “pre-Olympic” stock market rally of 2007 to much smaller premiums, and even to small discounts, as happened briefly on three occasions.

Normally, when onshore and offshore markets are separated by capital controls — and arbitrage is restricted, as is the case in China — onshore markets trade at a discount to the major offshore markets. This makes the Chinese A-share premium all the more anomalous. So why is the same share worth so much more on the mainland than it is offshore?